As the newest Expedition 26 crew members get used to their new home in orbit, the two veteran Flight Engineers Alexander Kaleri and Oleg Skripochka worked in the Russian side of the station. They participated in routine maintenance tasks and ongoing science experiments.

Similar to Pilot-M is the Interactions experiment. While both monitor a crew member’s performance, Interactions studies the impact of cultural and language differences among the crew including other interpersonal factors that affect group dynamics. A positive relationship among the crew as well as with ground support personnel is important for crew morale and mission success.

Kelly conducted an experiment that studies colloids which are substances microscopically interspersed throughout another substance. The Binary Colloidal Alloy Test-5 (BCAT-5) observes colloids and their interactions in microgravity. Examples of colloids include hair spray, milk and Styrofoam. Benefits may include improved engineering and industrial applications back on Earth.

The International Space Station was boosted into a higher orbit Wednesday when the docked Progress 39 spacecraft fired its thrusters for 21 minutes. A second and final reboost is planned for January completing the station’s orbital adjustment. The atmospheric drag of low-Earth orbit lowers a spacecraft’s orbit over time requiring periodic reboosts to maintain proper altitude.

The higher orbit puts the orbital laboratory into position for three new vehicles scheduled to dock next year. The second Japanese H2 Transfer Vehicle, the Progress 41 and space shuttle Discovery are scheduled to arrive over a period of two weeks in January and February. The Progress 40 spacecraft also will be in position for a Jan. 20 undocking.

Kelly, Coleman and Nespoli took a break from their work to send down their best wishes for the holiday season.

During his stay aboard the station, Kelly will post some of his photographs of Earth on Twitter for an online geography trivia game.